Gasoline engine powered pressure washers typically run at a fixed throttle position. If the engine is shut off, it has to be manually started which is time consuming as it requires the operator to return to the engine. Thus, the engine produces a continuous, high noise level when the gun trigger is both pulled to release high pressure spray, and when the trigger is released and no spray is being ejected. Further, when the engine runs the pump runs and if the spray gun is not spraying the pump re-circulates the water within the pump, causing the pump and water to heat. After a minute or two of re-circulating water the pump can overheat which may damage seals or bearings.
The Electric pressure-spraying machines produce no noise when the gun trigger is released, but produce noise when the trigger is pulled and the motor compresses fluid for spraying. Unfortunately, the electric powered compressors run off of 120 volt power sources and require an electrical cable that has safety risks around the water used in the spray washers. Further, because they do not require electrical cords, the fuel engine powered water compressors may be used in locations where electrical outlets are not available, and thus provide more versatile use, but the constant noise and exhaust is a disadvantage. There is thus a need for a gasoline pressure washer that reduces noise when the pressure is not being used to spray fluid, and that reduces exhaust. There is a further need for a gasoline pressure washer that automatically starts the engine when high pressure spray is needed and automatically stops the engine when no high pressure spray is needed.